Humidity in San Diego

~
The Sunny City by the Sea
~
Though San Diego is known for its sunny days, it can also get humid in the summer. Learn why humidity rates are on the rise and how to stay cool and dry.
Todd Sarouhan
Some of the links in this article are affiliate links. This means if you make purchases through them, I may be compensated at no extra cost to you. All opinions remain my own.
Humidity
How Humid is San Diego?
Causes of Humidity
Summer Humidity
Stay in San Diego
Popular Beaches

Highlights

Humidity Averages Chart
What Causes Humidity?
Summer Humidity
Average Humidity
Humidity Averages Chart
What Causes Humidity?
Summer Humidity

Just How Humid is San Diego?

Sunset at Law Street in North Pacific BeachBeautiful Day to Kite Surf in Sail Bay

San Diego doesn’t get much rainfall, so most people planning a vacation might assume that humidity levels are equally low. However, this isn’t entirely true; on the contrary, the county can be fairly humid, especially during the late summer months.

Humidity levels do vary based on specific location in San Diego, with the coastal and coastal inland areas being the most humid and the desert area generally being the least humid. Yearly averages, considering all areas hover in the 60% range to the mid-70% range in the summer months.

Relatively speaking though, San Diego’s humidity levels are considered comfortable year round! The air is not too dry where skin can crack but also not overly wet where you can expect to sweat at any moment.

San Diego Coastal - Humidity Averages Chart

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
HMD
63%
66%
67%
67%
71%
74%
75%
74%
73%
69%
66%
64%

What Causes Humidity in San Diego County?

White Water at North Pacific Beach
White Water at North Pacific Beach

Unlike other regions that derive their humidity from summer rains, most moisture in the air in San Diego doesn’t come from rain at all. Instead, it’s carried in by the winds that sweep in from the coast.

Other regions along the Pacific Coast, such as the Gulf of California and even the Gulf of Mexico, have high rates of moisture. When ocean winds bring this moisture inland, it creates humidity, even if it hasn’t rained in San Diego itself. In fact, the occasional shower can break the humidity, so a light rainfall every few weeks isn’t as inconvenient as it may seem.

Offshore tropical storms can also lead to rising humidity rates in San Diego, so it’s a good idea to keep an eye on the tropical storms predictions in the Pacific off of Mexico when planning a visit. While it’s unlikely that any rain or high winds will reach the coast, these spikes in humidity can be uncomfortable if you’re not keeping cool at the beach or taking a dip in a hotel pool.

San Diego also features a few natural phenomenons that can actually reduce humidity levels in the air! For example, some wind conditions can cause upwelling, which brings the cooler water in the depths of the ocean up closer to the surface. As the ocean’s surface temperature cools, less moisture is released into the atmosphere, keeping the weather dry and thus the humidity at bay.

San Diego Weather Forecast

August
68°F / 83°F
Sunny in August
September
66°F / 82°F
Sunny in September
October
61°F / 81°F
Sunny in October

Summer Humidity

Couple Going for a Swim at Grandview Surf Beach
Couple Going for a Swim at Grandview Surf Beach

Prior to the last decade or so, summer used to be fairly dry in San Diego. In fact, most years, droughts were more common from July through August. Recently, however, this trend has been changing, so that humidity during the summer exceeds that of winter.

This is partially due to decreasing rates of summer storms and the resulting rise in ocean temperatures. Previously, occasional rainfalls would churn the surface of the Pacific Ocean in coastal regions, evenly distributing the temperatures.

Without rain, and with extended sun instead, the ocean stays warmer for longer. This might sound great for those looking to go for a sunny swim or visit one of the more than 80 picturesque beaches, but it also has the effect of raising the dew point and creating a damp feeling in the air.

Featured Hotel
Tower 23 Hotel
Tower 23 Hotel
Beachfront
Beachfront
Boutique
Boutique
Couples
Couples
4 Stars4 Stars4 Stars4 Stars
At Tower 23 Hotel, you don’t have to compromise your lifestyle or your luxury when you travel. This boutique hotel in Pacific Beach is about more than comfort.
Prices Starting at $199
Check Availability

Average Humidity in San Diego Today

Boardwalk Bridge in Sail Bay
Boardwalk Bridge in Sail Bay

Nowadays, San Diego experiences relatively high levels of humidity throughout the year with an average humidity for the year at 69% as reported in the coastal area at the San Diego International Airport (SAN).

The months from July to September are generally when the weather can feel muggy at times with humidity levels averaging in the mid-70s. Do know though that humidity levels in the 70’s are not on the truly tropical level of a location like Orlando, Miami or even Costa Rica! Many travelers will enjoy a bit of moisture in the air when combined with sunny skies and cool ocean breezes.

However, muggy air is rare, and even in the peak of the summer, humidity levels are estimated to remain at a comfortable level for over 93% of the time. So, whether it's some gentle sightseeing or extreme sports you're planning, you won't be limited as to the range of outdoor activities you can do!

This Month's Forecast
66°F / 81°F
Sunny in July
Aug
68°F / 83°F
Sunny in August
Sep
66°F / 82°F
Sunny in September
Oct
61°F / 81°F
Sunny in October

Stay in San Diego

The Lodge at Torrey Pines
Luxury Hotel
5 Star Rating5 Star Rating5 Star Rating5 Star Rating5 Star Rating
The Lodge at Torrey Pines
from $343 / night
View Hotel
The Wayfarer San Diego
Family Friendly
3 Star Rating3 Star Rating3 Star Rating
The Wayfarer San Diego
from $236 / night
View Hotel
Tower 23 Hotel
Beachfront
4 Star Rating4 Star Rating4 Star Rating4 Star Rating
Tower 23 Hotel
from $199 / night
View Hotel
The Lafayette Hotel, Swim Club & Bungalows
Boutique Hotel
3 Star Rating3 Star Rating3 Star Rating
The Lafayette Hotel, Swim Club & Bungalows
from $127 / night
View Hotel
Show more San Diego Hotels >>
Looking for Something Different?
More San Diego Weather